 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.core.databinding.conversion;

 import java.math.BigInteger ;

 import com.ibm.icu.text.NumberFormat;

 /**
  * Converts a Number to a String using <code>NumberFormat.format(...)</code>.
  * This class is thread safe.
  *
  * @since 1.0
  */
 public class NumberToStringConverter extends Converter {
     private final NumberFormat numberFormat;
     private final Class fromType;
     private boolean fromTypeIsLong;
     private boolean fromTypeIsDecimalType;
     private boolean fromTypeIsBigInteger;

     /**
      * Constructs a new instance.
      * <p>
      * Private to restrict public instantiation.
      * </p>
      *
      * @param numberFormat
      * @param fromType
      */
     private NumberToStringConverter(NumberFormat numberFormat, Class fromType) {
         super(fromType, String .class);

         this.numberFormat = numberFormat;
         this.fromType = fromType;

         if (Integer .class.equals(fromType) || Integer.TYPE.equals(fromType)
                 || Long .class.equals(fromType) || Long.TYPE.equals(fromType)) {
             fromTypeIsLong = true;
         } else if (Float .class.equals(fromType) || Float.TYPE.equals(fromType)
                 || Double .class.equals(fromType)
                 || Double.TYPE.equals(fromType)) {
             fromTypeIsDecimalType = true;
         } else if (BigInteger .class.equals(fromType)) {
             fromTypeIsBigInteger = true;
         }
     }

     /**
      * Converts the provided <code>fromObject</code> to a <code>String</code>.
      * If the converter was constructed for an object type, non primitive, a
      * <code>fromObject</code> of <code>null</code> will be converted to an
      * empty string.
      *
      * @param fromObject
      * value to convert. May be <code>null</code> if the converter
      * was constructed for a non primitive type.
      * @see org.eclipse.core.databinding.conversion.IConverter#convert(java.lang.Object)
      */
     public Object convert(Object fromObject) {
         // Null is allowed when the type is not primitve.
 if (fromObject == null && !fromType.isPrimitive()) {
             return ""; //$NON-NLS-1$
 }

         Number number = (Number ) fromObject;
         String result = null;
         if (fromTypeIsLong) {
             synchronized (numberFormat) {
                 result = numberFormat.format(number.longValue());
             }
         } else if (fromTypeIsDecimalType) {
             synchronized (numberFormat) {
                 result = numberFormat.format(number.doubleValue());
             }
         } else if (fromTypeIsBigInteger) {
             synchronized (numberFormat) {
                 result = numberFormat.format((BigInteger ) number);
             }
         }

         return result;
     }

     /**
      * @param primitive
      * <code>true</code> if the type is a double
      * @return Double converter for the default locale
      */
     public static NumberToStringConverter fromDouble(boolean primitive) {
         return fromDouble(NumberFormat.getNumberInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return Double converter with the provided numberFormat
      */
     public static NumberToStringConverter fromDouble(NumberFormat numberFormat,
             boolean primitive) {
         return new NumberToStringConverter(numberFormat,
                 (primitive) ? Double.TYPE : Double .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the type is a long
      * @return Long converter for the default locale
      */
     public static NumberToStringConverter fromLong(boolean primitive) {
         return fromLong(NumberFormat.getIntegerInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return Long convert with the provided numberFormat
      */
     public static NumberToStringConverter fromLong(NumberFormat numberFormat,
             boolean primitive) {
         return new NumberToStringConverter(numberFormat,
                 (primitive) ? Long.TYPE : Long .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the type is a float
      * @return Float converter for the default locale
      */
     public static NumberToStringConverter fromFloat(boolean primitive) {
         return fromFloat(NumberFormat.getNumberInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return Float converter with the provided numberFormat
      */
     public static NumberToStringConverter fromFloat(NumberFormat numberFormat,
             boolean primitive) {
         return new NumberToStringConverter(numberFormat,
                 (primitive) ? Float.TYPE : Float .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the type is a int
      * @return Integer converter for the default locale
      */
     public static NumberToStringConverter fromInteger(boolean primitive) {
         return fromInteger(NumberFormat.getIntegerInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return Integer converter with the provided numberFormat
      */
     public static NumberToStringConverter fromInteger(
             NumberFormat numberFormat, boolean primitive) {
         return new NumberToStringConverter(numberFormat,
                 (primitive) ? Integer.TYPE : Integer .class);
     }

     /**
      * @return BigInteger convert for the default locale
      */
     public static NumberToStringConverter fromBigInteger() {
         return fromBigInteger(NumberFormat.getIntegerInstance());
     }

     /**
      * @param numberFormat
      * @return BigInteger converter with the provided numberFormat
      */
     public static NumberToStringConverter fromBigInteger(
             NumberFormat numberFormat) {
         return new NumberToStringConverter(numberFormat, BigInteger .class);
     }
 }

